There has been typically known a packaging bag with a zipper tape (hereinafter occasionally abbreviated as a packaging bag) provided by bonding the zipper tape to an inner surface of the bag body. When such a packaging bag is filled with powdery substances or liquids as a content, the content may leak toward a top seal beyond the zipper tape during transportation. Accordingly, a zipper tape with a separating structure provided between the zipper tape and the content and a packaging bag with the zipper tape have been known for preventing leakage of the content (see Patent Literatures 1 to 3).
The separating structure provided to the zipper tape is exemplified by a cutting portion, a part of which can be easily cut, and a seal that is easily peelable from an inner surface of a bag body. In opening the packaging bag, the cutting portion is cut or peeled to take out the content.
Patent Literature 1 discloses a packaging bag including a wide seal base provided to a belt-like base of a male member near the content. The seal base includes a linear cutting portion. The packaging bag is sealed by the linear cutting portion being bonded to an end of a belt-like base of a female member. The linear cutting portion is cut by a force in opening the zipper tape, thereby opening the packaging bag.
Similarly, Patent Literature 2 discloses in FIG. 10 that a thin and linear cutting portion is provided to a belt-like base of a male member near a content and the cutting portion is cut to open the packaging bag.
Patent Literature 3 discloses that a connecting portion is provided as a cutting portion by connecting ends of non-opening-side-flanges of a male member and a female member of a joint to each other and the connecting portion is cut to open the packaging bag. Patent Literature 3 also discloses that a protrusion having a triangular cross section is formed on each of the ends of the male member and the female member, thereby allowing a stress to concentrate on the cutting portion.